Can anyone help troubleshoot this truck? 1995 6.5 TD with 4L80E transmission. Pulled a load of horses to a show for my wife, unhooked, and drove 30 miles for breakfast. After truck sat for 1/2 hour, jumped in and found no forward gears. Sort of slips forward barely pulling its own weight. Reverse gear is fine, strong.

Changed fluid and filter, no difference. I could get it rolling downhill, then manually shift it from 1 to 2, etc. Once I got it to highway speed I seemed to have almost complete power to the drive train, but can barely get into my garage from a stop. Horses and trailer are stranded.

Also, can I work on this transmission without removing it from the truck?

You might have a problems with the shift solinoids or the the plate inside. Also have seen the check balls which are in the valve body can pull thru the plate. Probably would be best to run a pressure test on it.

Thanks for jumping on this. Can I get more specifics? Keeping in mind this is practically a roadside repair, can these solenoids be serviced with the tranny in the truck? And what of the fact that reverse works perfectly?

I think you burned your forward cltuches. This is the clutch which is applyed in all forward gears ( your direct link to the torque converter). If I am correct, you need a trans rebuild.
mike

This is what I am afraid of. However, is this the sort of thing that happens all of a sudden? Also, no metal fragments in the drained fluid, but lots of brown dirt.

Sounds like the forward clutch is cooked. These are awesome transmissions when built correctly. The stock teflon sealing rings shrink big time. A good builder will address all the rings in this tranny as well as the boost valve in the pump (Wears out and causes ultra high, parts breaking pressure).

Just being optimistic, I changed fluid/filter again, and cleaned everything I could access - no difference.

How would one go about finding a good rebuilder? Do I normally take the transmission out myself, or get towed? And when is it time to consider a replacement transmission (or a replacement truck, for that matter)?

Call Huckstorf Diesel & ask for Patrick. 414-421-7222. We are in Franklin, Wi. & I am not sure how far that is from you. Good Luck.
Patrick

Call Huckstorf Diesel & ask for Patrick. 414-421-7222. We are in Franklin, Wi. & I am not sure how far that is from you. Good Luck.
Patrick
Ashland is a long, long way from you patrick...ashland is very close to lake superior..:(